Characteristics of imaging findings for medication-related osteonecrosis of the jaw in patients with cemento-osseous dysplasia.

The present study aimed to elucidate the characteristics of imaging findings for medication-related osteonecrosis of the jaw (MRONJ) in patients with cemento-osseous dysplasia (COD). Images from patients with MRONJ and COD from among patients with osteomyelitis, including MRONJ, that were obtained from multidetector row computed tomography (MDCT), magnetic resonance imaging (MRI), panoramic radiographs, and dental radiographs, were retrospectively analysed. The characteristics of imaging findings for MRONJ in patients with COD were then analysed. Significant differences in the presence of sequester, periosteal reaction, pathological fracture, spread into soft tissue, cortical perforations, and separation between cortical and cancellous bone were observed between patients with MRONJ and those with non-medication-related osteomyelitis. In patients with MRONJ, no significant differences in inflammatory imaging features were observed between those with and without COD. Findings indicate that hyperdense lesions in the periapex of the involved teeth tend to remain in patients with MRONJ and COD. In addition, the sequestrum was sometimes composed of hyperdense lesions in the periapex of the involved teeth. Imaging findings in patients with MRONJ and COD were not necessarily different from those in patients with MRONJ without COD, which suggests that the diagnosis of patients with MRONJ and COD should be based on characteristic imaging findings, such as a sequestrum involving fusion between hyperdense structures and osteosclerosis. When performing necrotic bone removal, this characteristic should be considered during the procedure. Additionally, because COD is prone to inflammation, extra caution must be exercised regarding infection during and after the procedure compared with standard care.